Double-sided FCOB package carrier structure and manufacturing method

Abstract

The present invention discloses a double-sided FCOB package carrier structure and a manufacturing method, and relates to a double-sided FCOB package carrier structure and a manufacturing method, which are mainly used in semiconductor packaging. It includes a double-sided FPC substrate, and the double-sided FPC substrate includes an insulating layer and a covering film. By brushing a protective layer on the outer side of the carrier, the moisture in the outside air is effectively isolated from the contact with the epoxy resin of the adhesive, which causes the humidity to increase, and can solve the problem that the main component of the adhesive used in the current carrier, the epoxy resin, is highly sensitive to humidity. By covering the bare copper part of the carrier with a layer of OSP organic solder-preserving coating, the damage to the chip during the reflow process is effectively reduced. Whitening agent and white filler are added to the adhesive to reduce light absorption and improve light reflection efficiency.

Description

Technical Field

[0001] The invention relates to LED packaging, and in particular to a double-sided FCOB packaging carrier structure and a manufacturing method thereof. Background Art

[0002] FCOB (Flip Chip On Board) packaging technology is an advanced microelectronic packaging technology, mainly used in the LED display industry. It directly flips the chip and solders it on a flexible circuit board, achieving direct electrical connection between the chip and the circuit board. This technology has attracted much attention due to its high integration, excellent electrical performance and good reliability.

[0003] However, the inventors of this application found that the above technology has at least the following technical problems in the process of implementing the technical solution of the invention in the embodiment of this application:

[0004] 1. The main component of the adhesive used in the substrate, epoxy resin, is highly sensitive to humidity. If used in an environment with high humidity, it may cause packaging failure.

[0005] 2. After packaging, the product needs to go through a reflow process, which can easily damage the chip.

[0006] 3. Since the polyimide used in the insulating layer is yellow, it is prone to light absorption and has a low efficiency in reflecting light emitted by the chip. Summary of the invention

[0007] The embodiments of the present application provide a double-sided FCOB packaging carrier structure and a manufacturing method, thereby solving the problems in the prior art that epoxy resin is greatly affected by humidity, which easily leads to packaging failure, and the product is easily damaged to the chip during the reflow soldering process, thereby achieving the technical effects of stable packaging and stable application.

[0008] The embodiment of the present application provides a double-sided FCOB package carrier structure, including:

[0009] A double-sided FPC (Flexible Printed Circuit, also known as a soft circuit board, a flexible circuit board) substrate, the double-sided FPC substrate comprising:

[0010] A first insulating layer 71, wherein two sides of the first insulating layer 71 are covered with a first adhesive layer 61 and a second adhesive layer 62 respectively, the other side of the first adhesive layer 61 is covered with a first copper layer 4, and the other side of the second adhesive layer 62 is covered with a second copper layer 5, and a via 8 is provided between the first copper layer 4 and the second copper layer 5 for transmitting information at different levels;

[0011] A covering film, comprising:

[0012] The third adhesive layer 63 is used to bond the FPC substrate and the cover film. The side of the third adhesive layer 63 that is not in contact with the FPC substrate covers the second insulating layer 72, and the other side of the second insulating layer 72 covers the second protective layer 3;

[0013] A first protective layer 1 is provided on the side of the FPC substrate that is not in contact with the cover film, and a chip hole 2 is provided on the first protective layer 1 for placing the chip. The copper surface in the chip hole 2 is also covered with an anti-oxidation protective film 9.

[0014] Furthermore, the adhesive used in the first adhesive layer 61, the second adhesive layer 62, and the third adhesive layer 63 is made by mixing epoxy resin, epoxy rubber, a whitening agent, and any white filler.

[0015] Furthermore, the first insulating layer 71 and the second insulating layer 72 are made of polyimide polymer.

[0016] Furthermore, the first protective layer 1 and the second protective layer 3 are white thermosetting ink.

[0017] Furthermore, the anti-oxidation protective film 9 is an OSP organic protective coating.

[0018] Furthermore, the hole wall of the via hole 8 is a conductive carbon film layer, and the interior of the via hole 8 is filled with conductive material.

[0019] In addition, a method for manufacturing a double-sided FCOB package carrier is provided, comprising the following steps:

[0020] S1: Punch a via hole 8 on the FPC substrate, clean the wall of the via hole 8, and

[0021] A conductive carbon film layer is formed at the surface and copper is plated;

[0022] S2: Clean the copper surface and dry it, and laminate a photosensitive dry film on the first copper layer 4 and the second copper layer 5 by high temperature hot pressing;

[0023] S3: Exposure and development to form a clear circuit pattern on the FPC substrate to form a circuit layer;

[0024] S4: Printing white thermosetting ink on the first copper layer 4 with a dot screen to form a first protective layer 1 and setting a chip hole 2 on the first protective layer 1;

[0025] S5: Laminating a cover film on the second copper layer 5 by hot pressing;

[0026] S6: Curing the white thermosetting ink in an oven;

[0027] S7: using OSP organic solder-protecting coating to form an anti-oxidation protective film 9 on the chip hole 2;

[0028] Furthermore, the step of forming the conductive carbon film layer in S1 includes:

[0029] Q1: Micro-etching, the concentration of SPS used is 40-60g / L, the concentration of sulfuric acid is 3%-5%, and the temperature is between 23-27℃;

[0030] Q2: For the whole hole, the alkali equivalent of the solution used is 0.17-0.25N, the pH value is ≥9, and the temperature is 47-53℃

[0031] between;

[0032] Q3: Black hole, the solid content of the solution used is 2% to 4%, the pH value is ≥9.3, and the temperature is between 31 and 35°C.

[0033] Furthermore, a step may be added between S3 and S4: checking the circuit open and short circuits through electrical testing or AOI equipment to ensure electrical safety.

[0034] One or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages:

[0035] 1. Since a protective layer is applied on the outside of the carrier board to isolate the moisture in the outside air from the epoxy resin of the adhesive, the technical problem that the epoxy resin, the main component of the adhesive used in the current carrier board, is highly sensitive to humidity and may cause packaging failure if used in an environment with high humidity is effectively solved. This achieves the technical effect of making the carrier board stable and able to be used in various environmental humidity conditions.

[0036] 2. Since the bare copper part of the carrier board is covered with a layer of OSP organic solderability coating, the technical problem in the prior art that after packaging, the product needs to undergo a reflow soldering process, which can easily damage the chip, is solved. The carrier board has solderability and will not fail even after multiple reflow solderings, thus achieving the technical effect of stable product application.

[0037] 3. Since whitening agent and white filler are added to the adhesive and the chip hole 2 is separated from the insulating layer containing polyimide by the adhesive, the technical problem in the prior art that the polyimide used in the insulating layer of the carrier board is yellow and easily absorbs light, resulting in low reflection efficiency of the light emitted by the chip, is solved, and the technical effect of efficiently reflecting the light emitted by the LED chip is achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 This is a schematic diagram of the double-sided FCOB packaging substrate structure of this application.

[0039] Figure 2 This is a schematic diagram of the appearance of the double-sided FCOB packaging substrate of this application.

[0040] Figure 3 Flow chart of the manufacturing method of double-sided FCOB package substrate for this application

[0041] Figure 4 This is a flow chart of the method for forming a conductive carbon film layer of the present application.

[0042] Figure 5 This is the second flow chart of the double-sided FCOB packaging substrate manufacturing method of this application. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical solution and advantages of the double-sided FCOB package carrier structure and manufacturing method of the present application more clear, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention and are not used to limit the present invention.

[0044] Embodiment 1

[0045] like Figure 1 As shown in the figure, a double-sided FCOB package carrier structure of this embodiment includes a double-sided FPC substrate, a covering film and a first protective layer 1. The double-sided FPC substrate includes: a first insulating layer 71, the first insulating layer 71 covers the first adhesive layer 61 and the second adhesive layer 62 on both sides respectively, the first adhesive layer 61 covers the first copper layer 4 on the other side, and the second adhesive layer 62 covers the second copper layer 5 on the other side. A conductive hole 8 is set between the first copper layer 4 and the second copper layer 5 to transmit information at different levels. The covering film includes: a third adhesive layer 63, which is used to bond the FPC substrate and the covering film. The side of the third adhesive layer 63 that is not in contact with the FPC substrate covers the second insulating layer 72, and the other side of the second insulating layer 72 covers the second protective layer 3. The first protective layer 1 is set on the side of the FPC substrate that is not in contact with the covering film. A chip hole 2 is set on the first protective layer 1 for placing the chip. A layer of anti-oxidation protective film 9 is covered on the copper surface in the chip hole 2. The adhesive layer includes a first adhesive layer 61, a second adhesive layer 62 and a third adhesive layer 63, and the adhesive used is made of epoxy resin, epoxy rubber, a whitening agent and any white filler. The insulating layer includes a first insulating layer 71 and a second insulating layer 72, and is made of polyimide polymer.

[0046] The technical solutions in the above embodiments of the present application have at least the following technical effects or advantages:

[0047] In this embodiment, a whitening agent and any white filler are added to the adhesive, and the chip hole 2 and the first insulating layer 71 are separated by the first adhesive layer 61, so that a large amount of light emitted by the chip is reflected, the amount of light emitted by the chip absorbed by the yellow polyimide polymer in the first insulating layer 71 is reduced, and the utilization rate of electrical energy and light energy is improved.

[0048] Embodiment 2

[0049] like Figure 1 As shown in the figure, a double-sided FCOB package carrier structure of this embodiment includes a double-sided FPC substrate, a covering film and a first protective layer 1. The double-sided FPC substrate includes: a first insulating layer 71, the first insulating layer 71 covers the first adhesive layer 61 and the second adhesive layer 62 on both sides respectively, the first adhesive layer 61 covers the first copper layer 4 on the other side, and the second adhesive layer 62 covers the second copper layer 5 on the other side. A conductive hole 8 is set between the first copper layer 4 and the second copper layer 5 to transmit information at different levels. The covering film includes: a third adhesive layer 63, which is used to bond the FPC substrate and the covering film. The side of the third adhesive layer 63 that is not in contact with the FPC substrate covers the second insulating layer 72, and the other side of the second insulating layer 72 covers the second protective layer 3. The first protective layer 1 is set on the side of the FPC substrate that is not in contact with the covering film. A chip hole 2 is set on the first protective layer 1 for placing the chip. A layer of anti-oxidation protective film 9 is covered on the copper surface in the chip hole 2. The adhesive layer includes a first adhesive layer 61, a second adhesive layer 62 and a third adhesive layer 63, and the adhesives used are all made of epoxy resin, epoxy rubber, a whitening agent and any white filler. The protective layer includes a first protective layer 1 and a second protective layer 3, both of which are white thermosetting ink.

[0050] The technical solutions in the above embodiments of the present application have at least the following technical effects or advantages:

[0051] In this embodiment, by applying thermosetting ink on the surface of the carrier board in contact with the air, the epoxy resin in the adhesive used in the bonding layer can be isolated from the moisture in the air, thereby preventing the epoxy resin from being affected by the humidity of the use environment and causing packaging failure, thereby improving the success rate of chip packaging on the carrier board. At the same time, it also prevents the epoxy resin from being affected by the humidity of the use environment and shortening the service life of the entire product, thereby improving the service life of the product.

[0052] Embodiment 3

[0053] like Figure 1As shown in the figure, a double-sided FCOB package carrier structure of this embodiment includes a double-sided FPC substrate, a covering film and a first protective layer 1. The double-sided FPC substrate includes: a first insulating layer 71, the first insulating layer 71 covers the first adhesive layer 61 and the second adhesive layer 62 on both sides respectively, the first adhesive layer 61 covers the first copper layer 4 on the other side, and the second adhesive layer 62 covers the second copper layer 5 on the other side. A conductive hole 8 is set between the first copper layer 4 and the second copper layer 5 to transmit information at different levels. The covering film includes: a third adhesive layer 63, which is used to bond the FPC substrate and the covering film. The side of the third adhesive layer 63 that is not in contact with the FPC substrate covers the second insulating layer 72, and the other side of the second insulating layer 72 covers the second protective layer 3. The first protective layer 1 is set on the side of the FPC substrate that is not in contact with the covering film. A chip hole 2 is set on the first protective layer 1 for placing the chip. A layer of anti-oxidation protective film 9 is covered on the copper surface in the chip hole 2. The anti-oxidation protective film 9 has a thickness of 0.2-0.5 μm and is composed of high-temperature resistant OSP solution, which enables the product to be welded and will not fail even after multiple reflow soldering.

[0054] The technical solutions in the above embodiments of the present application have at least the following technical effects or advantages:

[0055] This embodiment forms an anti-oxidation protective film 9 on the bare copper part of the carrier board with an anti-high temperature OSP solution, thereby solving the technical problem that after the packaging is completed, the product needs to undergo a reflow soldering process, which can easily damage the chip. This makes the carrier board solderable and will not fail even after multiple reflow soldering processes, thereby achieving the technical effect that the product can be stably used.

[0056] Embodiment 4

[0057] like Figure 2 As shown, a double-sided FCOB package carrier structure of this embodiment is presented in the form of a light strip. When in use, the light-emitting chip is directly die-bonded in the chip hole 2. When the chip is working, the heat can be directly transferred to the carrier to form a heat conduction channel, reduce thermal resistance, and avoid heat accumulation in the chip area.

[0058] The technical solutions in the above embodiments of the present application have at least the following technical effects or advantages:

[0059] The FCOB light strip used in this embodiment has a linear light-emitting surface without light spots, which is user-friendly. Heat is easily conducted and can be quickly dissipated, avoiding the situation where a large amount of heat is accumulated to affect the normal operation of the chip and shorten the service life of the product, thereby achieving the technical effect of maintaining the normal operation of the product and extending the service life of the product.

[0060] Embodiment 5

[0061] like Figure 2 As shown, a double-sided FCOB package carrier structure of this embodiment has a chip hole 2 whose size can be adaptively adjusted according to the size of the light-emitting chip used, to avoid the loss of luminous flux caused by the copper surface exposed outside absorbing light and failing to reflect it during the chip light-emitting process.

[0062] The technical solutions in the above embodiments of the present application have at least the following technical effects or advantages:

[0063] The chip hole size of the FCOB light strip used in this embodiment can be adaptively adjusted according to the size of the light-emitting chip used, which solves the technical problem that the light emitted by the light-emitting chip is absorbed by the copper surface in large quantities, achieves the technical effect of improving the utilization rate of light energy and electrical energy, and has the advantages of energy saving and environmental protection.

[0064] Embodiment 6

[0065] like Figure 3 As shown, this embodiment provides a method for manufacturing a double-sided FCOB package carrier, comprising the following steps:

[0066] S1: punching a via hole 8 on the FPC substrate, cleaning the hole wall of the via hole 8, forming a conductive carbon film layer on the hole wall of the via hole 8, and copper plating;

[0067] S2: Clean the copper surface and dry it, and laminate a photosensitive dry film on the first copper layer 4 and the second copper layer 5 by high temperature hot pressing;

[0068] S3: Exposure and development to form a clear circuit pattern on the FPC substrate to form a circuit layer;

[0069] S4: Printing white thermosetting ink on the first copper layer 4 with a dot screen to form a first protective layer 1 and setting a chip hole 2 on the first protective layer 1;

[0070] S5: Laminating a cover film on the second copper layer 5 by hot pressing;

[0071] S6: Curing the white thermosetting ink in an oven;

[0072] S7: Using the OSP organic solder-protecting coating, a layer of anti-oxidation protective film 9 is formed on the chip hole 2. The technical solution in the above embodiment of the present application has at least the following technical effects or advantages:

[0073] The present method can be used to manufacture any carrier board of the above-mentioned embodiments one to six, possessing their advantages and achieving their corresponding technical effects.

[0074] Embodiment 7

[0075] like Figure 4 As shown, this embodiment provides a method for forming a conductive carbon film layer, and the specific steps include:

[0076] Q1: Micro-etching, the concentration of SPS used is 40gI, the concentration of sulfuric acid is 3% and the temperature is maintained at 23°C;

[0077] Q2: Whole hole, the alkali equivalent of the solution used is 0.17N, the pH value is ≥9, and the temperature is maintained at 47℃:

[0078] Q3: Black hole, the solid content of the solution used is 2%, the pH value is ≥9.3, and the temperature is maintained at 31°C.

[0079] The technical solutions in the above embodiments of the present application have at least the following technical effects or advantages:

[0080] The present method can form a conductive carbon film layer on the hole wall of the through hole 8 of the carrier board, connecting the first copper layer 4 and the second copper layer 5 of the FPC substrate, so that information can be transmitted at different levels, thereby improving information transmission efficiency and thermal conductivity efficiency.

[0081] Embodiment 8

[0082] like Figure 4 As shown, this embodiment provides a method for forming a conductive carbon film layer, and the specific steps include:

[0083] Q1: Micro-etching, the concentration of SPS used is 60gI, the concentration of sulfuric acid is 5% and the temperature is maintained at 27°C;

[0084] Q2: Whole hole, the alkali equivalent of the solution used is 0.25N, the pH value is ≥9, and the temperature is maintained at 53℃;

[0085] Q3: Black hole, the solid content of the solution used is 4%, the pH value is ≥9.3, and the temperature is maintained at 35℃.

[0086] The technical solutions in the above embodiments of the present application have at least the following technical effects or advantages:

[0087] The present method can form a conductive carbon film layer on the hole wall of the through hole 8 of the carrier board, connecting the first copper layer 4 and the second copper layer 5 of the FPC substrate, so that information can be transmitted at different levels, thereby improving information transmission efficiency and thermal conductivity efficiency.

[0088] Embodiment 9

[0089] like Figure 5 As shown, this embodiment provides a method for forming a conductive carbon film layer, and the specific steps include:

[0090] S1': punching a via hole 8 on the FPC substrate, cleaning the hole wall of the via hole 8, forming a conductive carbon film layer on the hole wall of the via hole 8, and copper plating;

[0091] S2': cleaning the copper surface and drying it, and applying a photosensitive dry film on the first copper layer 4 and the second copper layer 5 by high temperature hot pressing;

[0092] S3': Exposure and development to form a clear circuit pattern on the FPC substrate to form a circuit layer;

[0093] S4': Check the circuit for open and short circuit to ensure electrical safety;

[0094] S5': printing white thermosetting ink on the first copper layer 4 with a dot screen to form a first protective layer 1 and at the same time setting a chip hole 2 on the first protective layer 1;

[0095] S6': Laminating a cover film on the second copper layer 5 by hot pressing;

[0096] S7': curing the white thermosetting ink in an oven;

[0097] S8': Use OSP organic solderability coating to form an anti-oxidation protective film 9 on the chip hole 2.

[0098] The technical solutions in the above embodiments of the present application have at least the following technical effects or advantages:

[0099] Compared with the sixth embodiment, this embodiment adds a new step S4' in the steps. The inspection of the open and short circuits of the lines can verify whether there are any errors in the early production of the product. If there is a short circuit, timely repairs are performed to avoid continuing to process the short-circuited products in the later production steps, resulting in defective and bad products, and can achieve the technical effect of improving the yield and quality rate.

Claims

1. A double-sided FCOB package carrier, the double-sided FCOB package carrier comprising: A double-sided FPC substrate, the double-sided FPC substrate comprising: A first insulating layer (71), wherein two sides of the first insulating layer (71) are respectively covered with a first adhesive layer (61) and a second adhesive layer (62), The first adhesive layer (61) covers the first copper layer (4) on the other side, and the second adhesive layer (62) covers the second copper layer (5) on the other side. A conducting hole (8) is provided between the first copper layer (4) and the second copper layer (5) for transmitting information at different levels. A covering film, the covering film comprising a second insulating layer (72) and a second protective layer (3): A third adhesive layer (63) is used to bond the FPC substrate to the cover film, wherein the side of the third adhesive layer (63) not in contact with the FPC substrate is covered with the second insulating layer (72), and the other side of the second insulating layer (72) is covered with the second protective layer (3); A first protective layer (1) is provided on the side of the FPC substrate that is not in contact with the cover film, and a chip hole (2) is provided on the first protective layer (1) for placing a chip; and a layer of anti-oxidation protective film (9) is covered on the copper surface in the chip hole (2); The adhesive used in the first adhesive layer (61), the second adhesive layer (62) and the third adhesive layer (63) is made by mixing epoxy resin, epoxy rubber, a whitening agent and any white filler.

2. A double-sided FCOB package carrier as claimed in claim 1, characterized in that: The first insulating layer (71) and the second insulating layer (72) are composed of polyimide polymer.

3. A double-sided FCOB package carrier as claimed in claim 1, characterized in that: The first protective layer (1) and the second protective layer (3) are white thermosetting ink.

4. A double-sided FCOB package carrier as claimed in claim 1, characterized in that: The anti-oxidation protective film (9) is an OSP organic protective coating.

5. The double-sided FCOB package carrier according to claim 1, characterized in that: The hole wall of the via hole (8) is a conductive carbon film layer, and the interior of the via hole (8) is filled with conductive material.

6. A method for manufacturing a double-sided FCOB package carrier, suitable for manufacturing a double-sided FCOB package carrier as claimed in any one of claims 1 to 5, comprising the following steps: S1: punching a via hole (8) in the aforementioned double-sided FPC substrate, cleaning the hole wall of the via hole (8), forming a conductive carbon film layer on the hole wall of the via hole (8), and copper plating, wherein the step of forming the conductive carbon film layer includes: Q1: Micro-etching, the SPS concentration of the solution used is 40-60g / L, the sulfuric acid concentration is 3%-5%, and the temperature is between 23-27℃; Q2: For the whole hole, the alkali equivalent of the solution used is 0.17-0.25N, the pH value is ≥9, and the temperature is between 47 and 53°C; Q3: Black hole, the solid content of the solution used is 2% to 4%, the pH value is ≥9.3, and the temperature is between 31 and 35°C; S2: Cleaning and drying the copper surface, and applying a photosensitive dry film on the first copper layer (4) and the second copper layer (5) by high-temperature hot pressing; S3: Exposure and development to form a clear circuit pattern on the FPC substrate to form a circuit layer; S4: printing white thermosetting ink on the first copper layer (4) using a dot screen to form a first protective layer (1) and simultaneously providing a chip hole (2) in the first protective layer (1); S5: Laminating a covering film on the second copper layer (5) by hot pressing, the covering film comprising a second insulating layer (72), a third adhesive layer (63) and a second protective layer (3), the adhesive used in the third adhesive layer (63) being a mixture of epoxy resin, epoxy rubber, a whitening agent and any white filler; S6: Curing the white thermosetting ink in an oven; S7: using an OSP organic solderability protection coating to form an anti-oxidation protective film (9) on the chip hole (2).

7. A method for manufacturing a double-sided FCOB package carrier as claimed in claim 6, characterized in that: The OSP organic solder-protecting coating described in S7 is evenly applied on the chip hole (2), thereby forming an anti-oxidation protective film (9) on the chip hole (2).

8. A method for manufacturing a double-sided FCOB package substrate as claimed in claim 6, characterized in that: Between S3 and S4, add a step: check the circuit open and short circuit through electrical testing or AOI equipment to ensure electrical safety.

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